1) Car: 2000 Concorde LX1 3.2L
2) Issue: Intermittent sound from firewall (rapid clicking/knocking).
3) Frequency and Duration: 1 or 2 per second from 5 to 20 seconds.
4) Conditions: Can occur parked or moving but mostly at startup.

This sounds like a knocking in the steering column at the firewall but when exiting car and listening to engine it sounds like tappets clicking. Under hood, it sounds like noise is coming from area of steering column.

An article I stumbled upon describing a similar problem in a 1999 Chrysler focused upon the "Speed Proportional Steering Solenoid". There is no known linkage areas (tie rods etc) with significant play that could generate this sound. A slight vibration can be felt in the steering wheel in rhythm with the sound.

Q1) Could the solenoid be the source?
Q2) What is the most likely source and what should a plan for discovering the source look like?

 

For the benefit of anyone who is experiencing this problem, though the remedy obviously won’t be gleaned from postings here, there is a simple way of narrowing this down; pull the plug on the solenoid. My noise stopped when that was done (though the car is a little harder to steer). I gather a speed proportional steering solenoid is a step-up feature since the manual said all cars won’t have this item so I assume no harm would be done by merely pulling the plug.


The next step involves testing the solenoid which, as I understand it so far, receives it signals from the BCM (Body Control Module) which in turn receives information pertinent to this case from the TCM (Transmission Control Module).


At least at this point I know how to stop the noise and have narrowed the issue to three components with one (the solenoid) being the most probable root cause.